Looper mechanism for sewing machines



Feb. 28, 1933. F, F Z I 1,899,786

LOOPER MECHANISM FOR SEWING MACHINES Filed May 13 1929 3 Sheets-Sheet l Feb. 28, 1933. F. F. ZEIER 1,899,786

LOOPER MECHANISM FOR SEWING MACHINES Filed May 15 1929 3 Sheets-Sheet 2 "am: JML.

unt 9* Feb. 28, 1933. F. F. ZEIER I 1,899786 LOOPER MECHANISM FQR SEWING MACHINES Filed May 13 1929 3 Sheets-Sheet 3 Patented Feb. 28, 1933 STATES FREDERICK ZEIER, OF CHICAGO, ILLINOIS. ASSIGNOR 1'0 UNION SPECIAL ,MACI'TINE OOMLPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS PATENT OFFICE v Loormt monninsmron snwme MACHINES v j j -Applic atio n filed May 1 3, The inventionrelatesto new and useful mR em nts' inl'a loopermechanism for sew1ng machmes, and more particularly to a" mechanism for, giving to said looper a movementinto and out of the needle loop also a'needle avoiding movement. An object of the invention is to provide a looper actuating mechanism wherein all the movementsfor the looper are derived from themovementsof an eccentric strap.

A further object of the invention is to pro- ;vide alo'op'er' operating mechanism of the above type wherein the endwise movements of the eccentric strap are utilized for moving the looper into and out of the needle thread loopwhile the lateral movements of the ecmachine showing the looper operating mechanism in side view.

Fig. 3 is a sectional View on the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 3, but showing the eccentric strap in a different position.

The invention is directed to a looper operating mechanism for sewing machines. The looper is of the thread carrying type and is mounted on a carrier which is oscillated for moving the looper into and out of the needle thread loop. The looper carrier is in turn mounted on a looper support which is oscil- V lated for imparting the needle avoiding movement to the looper. On the main shaft of the machine is an eccentric. Cooperating with the eccentric is an eccentric strap which is connected at its free end to an arm carried by a rock shaft so that the longitudinal movements of the eccentric strap as the main shaft rotates oscillate said rock shaft. The rock shaft carries an arm which is connected through a link to the looper carrier and thus,

1929; Serial No. 362,680.

the oscillations of the shaft move the looper into and out of, the needle thread loop. The eccentric strap is provided with a proectlng portion adjacent the eccentric. Attached to this projecting portion :is a stud and a link connected to said stud isin turn connected to a slotted armwhich is fixed to the looper support.. During the rotations of the eccentricthe upper end of the eccentric strap will be given a lateral movement and through this link connection thelooper support is oscillated and a needle avoiding movement given to the looper.

Referring more in detail to the drawings, the invention 1s shown as applied to a sewing machine having a supporting bed 1 in which is mounted the main operating shaft 2. The

loopers are indicated at 3 and are of the thread carrying type. These loopers are mounted in a looper carrier 4 which is pivstud 7 and at its other end to a short shaft. 8. This short shaft 8 and the pivot'stud are a part of the looper support- The main shaft 2 carries an eccentric 9 (see Figs. 3 and 4:)

Cooperating with this eccentric 9 is an eccentric strap 10. The eccentric strap'is connected to a ball stud 11 on an arm 12 attached to a sleeve 13 fixed to a shaft l f. Mounted on this sleeve 13 is an arm 15. A link 16 is pivoted at 17 to the arm 15 and is pivoted at V 18 to the looper carrier 4. Asthe main shaft rotates the eccentric strap will be given a movement which will cause the ball stud 11 to move up and down in a vertical plane and impart oscillations to theshaft 14 and the.

arm 15 carried thereby. The oscillating arm 15 through the link 16 will oscillate the looper carrier and move 'the looper into 4 and out of the needle thread loops. The "eccentric strap 10 is provided with a'lateral extension 19. Mounted on the end'of the shaft 8"forming apart of the looper support is asleeve 20 carrying a depending arm 21 which is formed with a slot 22. Mounted in this slot 22 is a ball stud 23 which is capable of being shifted in the slot and secured in adjustedpositions by a nut 24. A link 25 engages the ball stud 1 and 4. When it moves from its extreme upper throw, as shown in Fig. 3, to its extreme lower throw, as shown in Fig. 4, it 7 will cause the upper end of the eccentric strap to move laterally turning about the center of the ball stud 11 as an axis. This lateral shift of the upper end of the eccen-' tric strap through the link willimpart oscillations to the arm 21 and the shaft 8 to which it is connected. This shaft 8, as-noted above, is a part of the looper support and will, therefore, give a lateral oscillation or needle avoiding movement to the looper. The extent of needle avoiding movement given to the looper may be varied by shifting the stud 23 in the slot 22. i

The extension 19 to which the ball stud 26 is connected is below the center of the main shaft even when the eccentric is at its extreme upper throw as viewed in Fig. 3. It is still further below the center of the shaft when the eccentric is at its extreme lower throw as viewed in Fig. 1. The lateral moveparted to the ball stud 26. When the eccenre ae looper support including a supporting shaft,

av main shaft at one side of, below. and parallel with the supporting shaft, an eccentric thereon, a rock shaft at ri vht an'les 'to the main shaft, an arm carried there'y, a link connecting said arm to said looper carrier, a second arm carried by said rock shaft, an ec-- centric strap cooperating with the eccentric and connectedto said last-named arm, an arm on the supporting shaft depending therefrom, a link pivotedto the eccentric strap ad jacent the eccentric and having an adjustable connection with the arm on the supporting shaft whereby the lateral movements of Hie eccentric strap impart an oscillation to said supporting shaft 7 V In testimony whereof, I ai'lix signatii 'l.

FREDERICK F. ZEIER;

- its forward the stud 26 will be moved tothe 7 .left as viewed in Fig. 3, which will oscillate the shaft 8 in a clockwise direction and move the looper so that it will pass the needle on the rear side thereof as viewed from the front of the machine. As the eccentric continues its rotation the looper is retracted and the eccentric strap will beshifted to the right as viewed in Figs. 3 and 4 and this will move the looper so that on its retracting path it is positioned on the opposite side of the needle path, that is, in front of the needle as viewed by the operator. This needleavoiding movement of the looper positions the looper thread triangle for theneedle to enter the same.

It Wlll be apparent from the above that a looper operating mechanism has been provided wherein the endwise movements of the J eccentric strap are utilized for moving the looper into and out of the needle thread loop and the lateral movements of the eccentric strap at the end thereof engaging the eccentric are utilized for impartingthe needle avoiding movement to the looper. This makes a very simple structure in which the 

